Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Background: This study compares ultrasound and surgical findings of anatomical variations in de Quervain’s disease. Methods: Seventy-four wrists from patients with unilateral de Quervain’s disease were examined through ultrasonography and surgery. Presence of intracompartment septum, abductor pollicis longus (APL) slips, and selective stenosis were verified by both methods. Two orthopedic surgeons assessed ultrasound findings for intra- and interobserver reliability. Results: Amongst 74 participants (43 women and 31 men), 60.8% had a complete septum, 31.1% had an incomplete septum, and 8.1% had no septum; 70.3% had multi-slip APL and 66.2% had extensor pollicis brevis stenosis. Surgical and ultrasonographic findings displayed a high level of sensitivity and specificity. Intraobserver reliability was high, and interobserver reliability was substantial. Conclusions The study confirms ultrasonography’s reliability in identifying anatomical variations in de Quervain’s disease, with high sensitivity, specificity, and substantial intra- and interobserver reliability, emphasizing its usefulness in preoperative assessment and planning.

Background: This study compares ultrasound and surgical findings of anatomical variations in de Quervain’s disease. Methods: Seventy-four wrists from patients with unilateral de Quervain’s disease were examined through ultrasonography and surgery. Presence of intracompartment septum, abductor pollicis longus (APL) slips, and selective stenosis were verified by both methods. Two orthopedic surgeons assessed ultrasound findings for intra- and interobserver reliability. Results: Amongst 74 participants (43 women and 31 men), 60.8% had a complete septum, 31.1% had an incomplete septum, and 8.1% had no septum; 70.3% had multi-slip APL and 66.2% had extensor pollicis brevis stenosis. Surgical and ultrasonographic findings displayed a high level of sensitivity and specificity. Intraobserver reliability was high, and interobserver reliability was substantial. Conclusions The study confirms ultrasonography’s reliability in identifying anatomical variations in de Quervain’s disease, with high sensitivity, specificity, and substantial intra- and interobserver reliability, emphasizing its usefulness in preoperative assessment and planning.

Background: This study compares ultrasound and surgical findings of anatomical variations in de Quervain’s disease. Methods: Seventy-four wrists from patients with unilateral de Quervain’s disease were examined through ultrasonography and surgery. Presence of intracompartment septum, abductor pollicis longus (APL) slips, and selective stenosis were verified by both methods. Two orthopedic surgeons assessed ultrasound findings for intra- and interobserver reliability. Results: Amongst 74 participants (43 women and 31 men), 60.8% had a complete septum, 31.1% had an incomplete septum, and 8.1% had no septum; 70.3% had multi-slip APL and 66.2% had extensor pollicis brevis stenosis. Surgical and ultrasonographic findings displayed a high level of sensitivity and specificity. Intraobserver reliability was high, and interobserver reliability was substantial. Conclusions The study confirms ultrasonography’s reliability in identifying anatomical variations in de Quervain’s disease, with high sensitivity, specificity, and substantial intra- and interobserver reliability, emphasizing its usefulness in preoperative assessment and planning.

Background: This study compares ultrasound and surgical findings of anatomical variations in de Quervain’s disease. Methods: Seventy-four wrists from patients with unilateral de Quervain’s disease were examined through ultrasonography and surgery. Presence of intracompartment septum, abductor pollicis longus (APL) slips, and selective stenosis were verified by both methods. Two orthopedic surgeons assessed ultrasound findings for intra- and interobserver reliability. Results: Amongst 74 participants (43 women and 31 men), 60.8% had a complete septum, 31.1% had an incomplete septum, and 8.1% had no septum; 70.3% had multi-slip APL and 66.2% had extensor pollicis brevis stenosis. Surgical and ultrasonographic findings displayed a high level of sensitivity and specificity. Intraobserver reliability was high, and interobserver reliability was substantial. Conclusions The study confirms ultrasonography’s reliability in identifying anatomical variations in de Quervain’s disease, with high sensitivity, specificity, and substantial intra- and interobserver reliability, emphasizing its usefulness in preoperative assessment and planning.

Anastomosing hemangioma (AH) is an exceptionally rare benign vascular neoplasm that can closely mimic renal cell carcinoma (RCC) on radiologic and histopathologic evaluation. We report a 63-year-old male kidney transplant recipient who developed a small enhancing renal mass during pretransplant assessment for a second kidney transplantation. The patient had received a deceased donor kidney transplantation in April 1994 and resumed maintenance hemodialysis in April 2025 due to chronic allograft failure. During evaluation for a planned living donor kidney transplantation from his son, abdominal contrast-enhanced computed tomography revealed a 1.4 cm well-circumscribed enhancing mass in the upper pole of the transplanted kidney, highly suspicious for RCC. Magnetic resonance imaging demonstrated a T2 hyperintense lesion with heterogeneous and delayed enhancement, and positron emission tomography-computed tomography showed no hypermetabolic uptake or metastasis. Transplant nephrectomy was performed to exclude malignancy. Histopathologic examination revealed anastomosing capillary-sized vascular channels lined by bland endothelial cells without atypia, consistent with AH. Immunohistochemical staining was positive for CD34 and ERG, confirming endothelial differentiation. This case emphasizes the diagnostic challenge of distinguishing AH from RCC in transplant recipients and highlights the importance of accurate pathologic diagnosis to prevent unnecessary delay in subsequent kidney transplantation.

Anti-glomerular basement membrane (GBM) antibody disease is a rare autoimmune disorder characterized by autoantibodies directed against antigens within the GBM, primarily affecting the kidneys and lungs. This severe form of glomerulonephritis has an incidence of less than two cases per million individuals with crescentic glomerulonephritis. The coexistence of immunoglobulin A (IgA) nephropathy and anti-GBM disease is rare. Here, we present a case of concurrent anti-GBM antibody disease and IgA nephropathy. A 49-year-old male presented with fever, azotemia, proteinuria, and hematuria. Biopsy of the kidney revealed crescentic glomerulonephritis with linear IgG deposition along the GBM and IgA deposition in the mesangium. Elevated serum levels of anti-GBM antibody (311 U/mL) confirmed the diagnosis of concurrent anti-GBM antibody disease and IgA nephropathy. Despite treatment with methylprednisolone, cyclophosphamide, and plasma exchange, renal function deteriorated, necessitating hemodialysis.

The Korean Society of Infectious Diseases has been regularly publishing guidelines for adult immunization since 2007. Following the release of coronavirus disease 2019 (COVID-19) vaccination recommendations in 2023, significant changes have occurred due to the emergence of new variant strains and the waning immunity from previous vaccinations. This article provides a comprehensive update as of November 2024, incorporating the latest evidence and guidelines. Focusing on the 2024–2025 season, this article reviews vaccines currently authorized in Korea and assesses their effectiveness against the predominant JN.1 lineage variants. The updated recommendations prioritize high-risk groups, including adults aged 65 and older, individuals with underlying medical conditions, residents of facilities vulnerable to infection, pregnant women, and healthcare workers, for vaccination with updated vaccines targeting the JN.1 strain. Additionally, COVID-19 vaccination is available for all individuals aged 6 months and older. For most adults, a single-dose strategy is emphasized, while tailored schedules may be recommended for immunocompromised individuals. This update aims to optimize vaccination strategies in Korea to ensure comprehensive protection for high-risk populations.